1. Field of the Invention
The present invention relates generally to digital communication apparatuses including cellular phones, PDAs (Personal Digital Assistants), HHPs (Hand Held Phones), camera phones, game phones, and message phones, and more particularly to a sliding-type portable digital communication apparatus having keys that move up and down by rotational motion caused by sliding the slidable portion of the portable digital communication apparatus.
2. Description of the Related Art
In general, “portable communication apparatus” refers to an electronic apparatus that a user can carry to perform wireless communication with a desired partner. In consideration of portability, designs of such portable communication apparatuses have tended toward compactness, slimness, and lightness, and more recently, toward multimedia availability, having a wider variety of functions. More specifically, future portable communication apparatuses are expected to incorporate greater multi-functionality and multi-purpose utilization, as well as greater compactness and lightness. Also, these future portable communication apparatuses will be modified to be suitable for various multimedia environments or Internet environments.
Commonly, conventional portable communication apparatuses are classified into various categories according to their appearance, such as bar-type portable communication apparatuses, flip-type portable communication apparatuses, and folder-type portable communication apparatuses. The bar-type communication apparatuses have a single housing shaped like a bar. The flip-type communication apparatuses have a flip portion, which is rotatably coupled to a bar-shaped housing by a hinge device. The folder-type communication apparatuses have a folder which is connected to a single bar-shaped housing by a hinge device in such a manner that the folder can be rotated to fold on or unfold from the housing.
Portable communication apparatuses may also be classified into neck wearable type communication apparatuses and wrist wearable type communication apparatuses according to the position at or the way in which a user puts on the communication apparatus. Obviously, the neck wearable type communication apparatus is one that a user wears around the neck using a string, and the wrist wearable type communication apparatus is one, which a user wears around the wrist.
In addition, portable communication apparatuses may be classified into rotation-type communication apparatuses and sliding-type communication apparatuses according to ways of opening and closing the communication apparatuses. In the rotation-type portable communication apparatuses, two housings are coupled to each other in such a manner that one housing rotates to be opened or closed relative to the other while they face each other. In the sliding-type portable communication apparatuses, two housings are coupled to each other in such a manner that one housing slides along a longitudinal direction to be opened or closed relative to the other. These variously classified portable communication apparatuses are easily understood by those skilled in the art.
Recently, conventional portable communication apparatuses tend to have a function of transmitting data at a high speed in addition to the basic function of performing voice communication. That is, according to the increase of demand by consumers, portable communication apparatuses now tend to provide a service using a wireless communication technology capable of transmitting data at a high speed.
Further, recent portable communication apparatuses tend to be equipped with a camera lens for transmission of video signals. That is, current portable communication apparatuses have an external or imbedded camera lens module, which enables a user to perform video communication with a desired partner or to take photographs of a desired subject.
However, keypads used in conventional portable communication apparatuses have a problem in that the top surfaces of the keys are positioned on the same plane and more accuracy in key pressing operation is necessary. More specifically, in practice, users must accurately press the top surface of a desired key with a finger to input data accurately. Without such operation, erroneous key pressing occurs frequently and the speed of key pressing operation decreases. Furthermore, a data input device is necessary that can implement key pressing operation more rapidly and accurately in a busy or urgent situation.